1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
|
//
// HFSharedMemoryByteSlice.m
// HexFiend_2
//
// Copyright 2008 ridiculous_fish. All rights reserved.
//
#import <HexFiend/HFByteSlice_Private.h>
#import <HexFiend/HFSharedMemoryByteSlice.h>
#define MAX_FAST_PATH_SIZE (1 << 13)
#define MAX_TAIL_LENGTH (sizeof ((HFSharedMemoryByteSlice *)NULL)->inlineTail / sizeof *((HFSharedMemoryByteSlice *)NULL)->inlineTail)
@implementation HFSharedMemoryByteSlice
- (instancetype)initWithUnsharedData:(NSData *)unsharedData {
self = [super init];
REQUIRE_NOT_NULL(unsharedData);
NSUInteger dataLength = [unsharedData length];
NSUInteger inlineAmount = MIN(dataLength, MAX_TAIL_LENGTH);
NSUInteger sharedAmount = dataLength - inlineAmount;
HFASSERT(inlineAmount <= UCHAR_MAX);
inlineTailLength = (unsigned char)inlineAmount;
length = sharedAmount;
if (inlineAmount > 0) {
[unsharedData getBytes:inlineTail range:NSMakeRange(dataLength - inlineAmount, inlineAmount)];
}
if (sharedAmount > 0) {
data = [[NSMutableData alloc] initWithBytes:[unsharedData bytes] length:sharedAmount];
}
return self;
}
// retains, does not copy
- (instancetype)initWithData:(NSMutableData *)dat {
REQUIRE_NOT_NULL(dat);
return [self initWithData:dat offset:0 length:[dat length]];
}
- (instancetype)initWithData:(NSMutableData *)dat offset:(NSUInteger)off length:(NSUInteger)len {
self = [super init];
REQUIRE_NOT_NULL(dat);
HFASSERT(off + len >= off); //check for overflow
HFASSERT(off + len <= [dat length]);
offset = off;
length = len;
data = [dat retain];
return self;
}
- (instancetype)initWithSharedData:(NSMutableData *)dat offset:(NSUInteger)off length:(NSUInteger)len tail:(const void *)tail tailLength:(NSUInteger)tailLen {
self = [super init];
if (off || len) REQUIRE_NOT_NULL(dat);
if (tailLen) REQUIRE_NOT_NULL(tail);
HFASSERT(tailLen <= MAX_TAIL_LENGTH);
HFASSERT(off + len >= off);
HFASSERT(off + len <= [dat length]);
offset = off;
length = len;
data = [dat retain];
HFASSERT(tailLen <= UCHAR_MAX);
inlineTailLength = (unsigned char)tailLen;
memcpy(inlineTail, tail, tailLen);
HFASSERT([self length] == tailLen + len);
return self;
}
- (void)dealloc {
[data release];
[super dealloc];
}
- (unsigned long long)length {
return length + inlineTailLength;
}
- (void)copyBytes:(unsigned char *)dst range:(HFRange)lrange {
HFASSERT(HFSum(length, inlineTailLength) >= HFMaxRange(lrange));
NSRange requestedRange = NSMakeRange(ll2l(lrange.location), ll2l(lrange.length));
NSRange dataRange = NSMakeRange(0, length);
NSRange tailRange = NSMakeRange(length, inlineTailLength);
NSRange dataRangeToCopy = NSIntersectionRange(requestedRange, dataRange);
NSRange tailRangeToCopy = NSIntersectionRange(requestedRange, tailRange);
HFASSERT(HFSum(dataRangeToCopy.length, tailRangeToCopy.length) == lrange.length);
if (dataRangeToCopy.length > 0) {
HFASSERT(HFSum(NSMaxRange(dataRangeToCopy), offset) <= [data length]);
const void *bytes = [data bytes];
memcpy(dst, bytes + dataRangeToCopy.location + offset, dataRangeToCopy.length);
}
if (tailRangeToCopy.length > 0) {
HFASSERT(tailRangeToCopy.location >= length);
HFASSERT(NSMaxRange(tailRangeToCopy) - length <= inlineTailLength);
memcpy(dst + dataRangeToCopy.length, inlineTail + tailRangeToCopy.location - length, tailRangeToCopy.length);
}
}
- (HFByteSlice *)subsliceWithRange:(HFRange)lrange {
if (HFRangeEqualsRange(lrange, HFRangeMake(0, HFSum(length, inlineTailLength)))) return [[self retain] autorelease];
HFByteSlice *result;
HFASSERT(lrange.length > 0);
HFASSERT(HFSum(length, inlineTailLength) >= HFMaxRange(lrange));
NSRange requestedRange = NSMakeRange(ll2l(lrange.location), ll2l(lrange.length));
NSRange dataRange = NSMakeRange(0, length);
NSRange tailRange = NSMakeRange(length, inlineTailLength);
NSRange dataRangeToCopy = NSIntersectionRange(requestedRange, dataRange);
NSRange tailRangeToCopy = NSIntersectionRange(requestedRange, tailRange);
HFASSERT(HFSum(dataRangeToCopy.length, tailRangeToCopy.length) == lrange.length);
NSMutableData *resultData = NULL;
NSUInteger resultOffset = 0;
NSUInteger resultLength = 0;
const unsigned char *tail = NULL;
NSUInteger tailLength = 0;
if (dataRangeToCopy.length > 0) {
resultData = data;
HFASSERT(resultData != NULL);
resultOffset = offset + dataRangeToCopy.location;
resultLength = dataRangeToCopy.length;
HFASSERT(HFSum(resultOffset, resultLength) <= [data length]);
}
if (tailRangeToCopy.length > 0) {
tail = inlineTail + tailRangeToCopy.location - length;
tailLength = tailRangeToCopy.length;
HFASSERT(tail >= inlineTail && tail + tailLength <= inlineTail + inlineTailLength);
}
HFASSERT(resultLength + tailLength == lrange.length);
result = [[[[self class] alloc] initWithSharedData:resultData offset:resultOffset length:resultLength tail:tail tailLength:tailLength] autorelease];
HFASSERT([result length] == lrange.length);
return result;
}
- (HFByteSlice *)byteSliceByAppendingSlice:(HFByteSlice *)slice {
REQUIRE_NOT_NULL(slice);
const unsigned long long sliceLength = [slice length];
if (sliceLength == 0) return self;
const unsigned long long thisLength = [self length];
HFASSERT(inlineTailLength <= MAX_TAIL_LENGTH);
NSUInteger spaceRemainingInTail = MAX_TAIL_LENGTH - inlineTailLength;
if (sliceLength <= spaceRemainingInTail) {
/* We can do our work entirely within the tail */
NSUInteger newTailLength = (NSUInteger)sliceLength + inlineTailLength;
unsigned char newTail[MAX_TAIL_LENGTH];
memcpy(newTail, inlineTail, inlineTailLength);
[slice copyBytes:newTail + inlineTailLength range:HFRangeMake(0, sliceLength)];
HFByteSlice *result = [[[[self class] alloc] initWithSharedData:data offset:offset length:length tail:newTail tailLength:newTailLength] autorelease];
HFASSERT([result length] == HFSum(sliceLength, thisLength));
return result;
}
else {
/* We can't do our work entirely in the tail; see if we can append some shared data. */
HFASSERT(offset + length >= offset);
if (offset + length == [data length]) {
/* We can append some shared data. But impose some reasonable limit on how big our slice can get; this is 16 MB */
if (HFSum(thisLength, sliceLength) < (1ULL << 24)) {
NSUInteger newDataOffset = offset;
NSUInteger newDataLength = length;
unsigned char newDataTail[MAX_TAIL_LENGTH];
unsigned char newDataTailLength = MAX_TAIL_LENGTH;
NSMutableData *newData = (data ? data : [[[NSMutableData alloc] init] autorelease]);
NSUInteger sliceLengthInt = ll2l(sliceLength);
NSUInteger newTotalTailLength = sliceLengthInt + inlineTailLength;
HFASSERT(newTotalTailLength >= MAX_TAIL_LENGTH);
NSUInteger amountToShiftIntoSharedData = newTotalTailLength - MAX_TAIL_LENGTH;
NSUInteger amountToShiftIntoSharedDataFromTail = MIN(amountToShiftIntoSharedData, inlineTailLength);
NSUInteger amountToShiftIntoSharedDataFromNewSlice = amountToShiftIntoSharedData - amountToShiftIntoSharedDataFromTail;
if (amountToShiftIntoSharedDataFromTail > 0) {
HFASSERT(amountToShiftIntoSharedDataFromTail <= inlineTailLength);
[newData appendBytes:inlineTail length:amountToShiftIntoSharedDataFromTail];
newDataLength += amountToShiftIntoSharedDataFromTail;
}
if (amountToShiftIntoSharedDataFromNewSlice > 0) {
HFASSERT(amountToShiftIntoSharedDataFromNewSlice <= [slice length]);
NSUInteger dataLength = offset + length + amountToShiftIntoSharedDataFromTail;
HFASSERT([newData length] == dataLength);
[newData setLength:dataLength + amountToShiftIntoSharedDataFromNewSlice];
[slice copyBytes:[newData mutableBytes] + dataLength range:HFRangeMake(0, amountToShiftIntoSharedDataFromNewSlice)];
newDataLength += amountToShiftIntoSharedDataFromNewSlice;
}
/* We've updated our data; now figure out the tail */
NSUInteger amountOfTailFromNewSlice = sliceLengthInt - amountToShiftIntoSharedDataFromNewSlice;
HFASSERT(amountOfTailFromNewSlice <= MAX_TAIL_LENGTH);
[slice copyBytes:newDataTail + MAX_TAIL_LENGTH - amountOfTailFromNewSlice range:HFRangeMake(sliceLengthInt - amountOfTailFromNewSlice, amountOfTailFromNewSlice)];
/* Copy the rest, if any, from the end of self */
NSUInteger amountOfTailFromSelf = MAX_TAIL_LENGTH - amountOfTailFromNewSlice;
HFASSERT(amountOfTailFromSelf <= inlineTailLength);
if (amountOfTailFromSelf > 0) {
memcpy(newDataTail, inlineTail + inlineTailLength - amountOfTailFromSelf, amountOfTailFromSelf);
}
HFByteSlice *result = [[[[self class] alloc] initWithSharedData:newData offset:newDataOffset length:newDataLength tail:newDataTail tailLength:newDataTailLength] autorelease];
HFASSERT([result length] == HFSum([slice length], [self length]));
return result;
}
}
}
return nil;
}
@end
|
